1. Field of the Invention
The present invention generally relates to an image forming apparatus, such as a printer, or a facsimile device or a corresponding process cartridge, and more particularly relates to a cleaning member.
2. Description of the Related Art
In a conventional image forming apparatus, a cleaning member is used to remove excess developer from an image carrier, for example. The cleaning member is attached to a case of the apparatus and includes an elastic blade that is connected to a support plate having an attaching portion that is fixed to the case such that the elastic blade contacts the image carrier. The present inventors have recognized that a penetration length (generally measured from the attaching portion to the blade contact with the image carrier) and contact angle against image carrier are important to decide cleaning efficiency. Moreover, in processing a plate, accuracy of the cleaning member contact to the image carrier decreases according to the amount of processing done on the plate. Still further it is generally known that a fold portion and/or a convex portion on the support plate are used to add strength to the plate member.
Japanese patent laid-open No. Hei7-175393 discloses a cleaning member in which the support plate has at least one fold portion between the blade and the attaching part to add strength. While this configuration maintains a good toner removing efficiency for high speed machines, it decreases the accuracy of blade contact on the image carrier. Similarly, Japanese patent laid-open No 2002-214886 discloses another cleaning member in which a support plate member has a convex portion made by a pressing process, which adds strength to the cleaning member. However, this reference does not address the need for accuracy of blade contact with the image carrier. Because the cleaning member of the above described publications do not provide accurate contact between the blade and image carrier, the devices disclosed therein generally do not remove toner from the image carrier correctly. Moreover, the present inventors have recognized that inaccuracy of the contact point between the blade and image carrier may undesirably transform the image carrier.
Furthermore, it is generally known that when a cleaning blade non-uniformly contacts an image carrier, undesirable noise results, perhaps due to oscillations of the cleaning blade. There have been many suggestions of how to prevent such noises. For example, use of interior heavy goods, an elastic member, a vibration absorption member are well-known methods of attempting to prevent noise caused by oscillation of the cleaning member. However, it has been difficult to completely prevent noises because of the many factors that contribute to this problem, which include a photoreceptor structure, a toner type, and a cleaning blade type, as well as temperature and humidity of the operating environment.